I received a text from a friend that she didn't send. Is there an explanation for this?

Question

So I was texting my friend, we both have iPhones and are both using iMessage to text each other. We got into a rather personal conversation (not that important). But in the middle of the conversation I received a text message (SMS) instead of an iMessage which we'd both been using, but then immediately back to iMessage, so I thought nothing of it. Then later it happened again, I got another text message in the middle of our iMessage conversation, and then back to iMessage. Although this time it was a strange question to which I inquired about and my friend was confused as to what I was talking about. I screenshotted the text message I received in the middle of OUR iMessage conversation and sent it to her. She said "I never sent that" and was adamant about it. I believe her, although I am not by any means ruling out that she lied to me. All the text messages came from the same number that I've always texted from previous phones and iMessage'd since we've had out iPhones. What makes me both scared (and suspicious of my friend in a way) is that in the text messages I got, they referenced the very personal conversation that her and I were having through iMessage. She swears by god that she neither told anybody about our conversation, nor let anybody see her phone. Is there a legitimate explanation for what has occurred? It has made me very paranoid as to the fact that either she lied to me, or perhaps to the even more frightening fact that our conversation is being watched and apparently intervened into by an unknown stranger, by which an explanation may help. However unlikely that is, I will not rule it out. Technology has come far and can do many things. Any insight/feedback as to a possible explanation or anything to ease my stress and paranoia would be greatly appreciated. Keep in mind, the messages I got that are in question are from her phone number, not her iMessage/apple ID address/email address. She swears she did not send then, which I trust, but they came from her phone number.
<Email Edited by Host>

Answer 1

Gave me a URL on Apple.ie...
What was that URL? Don't post the whole thing; just the part between the double // and the first single / or ? character. For example, if it was
http://something.apple.ie.something/blahblah
or
http://something.apple.ie.something?blah=blahblah
then just post
something.apple.ie.something